Description
In the Linux kernel, the following vulnerability has been resolved:
net: ipv4: fix memory leak in ip_mc_add1_src
BUG: memory leak
unreferenced object 0xffff888101bc4c00 (size 32):
comm "syz-executor527", pid 360, jiffies 4294807421 (age 19.329s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
01 00 00 00 00 00 00 00 ac 14 14 bb 00 00 02 00 ................
backtrace:
[<00000000f17c5244>] kmalloc include/linux/slab.h:558 [inline]
[<00000000f17c5244>] kzalloc include/linux/slab.h:688 [inline]
[<00000000f17c5244>] ip_mc_add1_src net/ipv4/igmp.c:1971 [inline]
[<00000000f17c5244>] ip_mc_add_src+0x95f/0xdb0 net/ipv4/igmp.c:2095
[<000000001cb99709>] ip_mc_source+0x84c/0xea0 net/ipv4/igmp.c:2416
[<0000000052cf19ed>] do_ip_setsockopt net/ipv4/ip_sockglue.c:1294 [inline]
[<0000000052cf19ed>] ip_setsockopt+0x114b/0x30c0 net/ipv4/ip_sockglue.c:1423
[<00000000477edfbc>] raw_setsockopt+0x13d/0x170 net/ipv4/raw.c:857
[<00000000e75ca9bb>] __sys_setsockopt+0x158/0x270 net/socket.c:2117
[<00000000bdb993a8>] __do_sys_setsockopt net/socket.c:2128 [inline]
[<00000000bdb993a8>] __se_sys_setsockopt net/socket.c:2125 [inline]
[<00000000bdb993a8>] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2125
[<000000006a1ffdbd>] do_syscall_64+0x40/0x80 arch/x86/entry/common.c:47
[<00000000b11467c4>] entry_SYSCALL_64_after_hwframe+0x44/0xae
In commit 24803f38a5c0 ("igmp: do not remove igmp souce list info when set
link down"), the ip_mc_clear_src() in ip_mc_destroy_dev() was removed,
because it was also called in igmpv3_clear_delrec().
Rough callgraph:
inetdev_destroy
-> ip_mc_destroy_dev
-> igmpv3_clear_delrec
-> ip_mc_clear_src
-> RCU_INIT_POINTER(dev->ip_ptr, NULL)
However, ip_mc_clear_src() called in igmpv3_clear_delrec() doesn't
release in_dev->mc_list->sources. And RCU_INIT_POINTER() assigns the
NULL to dev->ip_ptr. As a result, in_dev cannot be obtained through
inetdev_by_index() and then in_dev->mc_list->sources cannot be released
by ip_mc_del1_src() in the sock_close. Rough call sequence goes like:
sock_close
-> __sock_release
-> inet_release
-> ip_mc_drop_socket
-> inetdev_by_index
-> ip_mc_leave_src
-> ip_mc_del_src
-> ip_mc_del1_src
So we still need to call ip_mc_clear_src() in ip_mc_destroy_dev() to free
in_dev->mc_list->sources.
Understanding This Vulnerability
This Common Vulnerabilities and Exposures (CVE) entry provides detailed information about a security vulnerability that has been publicly disclosed. CVEs are standardized identifiers assigned by MITRE Corporation to track and catalog security vulnerabilities across software and hardware products.
The severity rating (MEDIUM) indicates the potential impact of this vulnerability based on the CVSS (Common Vulnerability Scoring System) framework. Higher severity ratings typically indicate vulnerabilities that could lead to more significant security breaches if exploited. Security teams should prioritize remediation efforts based on severity, exploit availability, and the EPSS (Exploit Prediction Scoring System) score, which predicts the likelihood of exploitation in the wild.
If this vulnerability affects products or systems in your infrastructure, we recommend reviewing the affected products section, checking for available patches or updates from vendors, and implementing recommended workarounds or solutions until a permanent fix is available. Organizations should also monitor security advisories and threat intelligence feeds for updates about active exploitation of this vulnerability.